Power and computational load management techniques in video processing

ABSTRACT

Techniques for managing power consumption and computational load on a processor during video processing and decoding are provided. One representative embodiment discloses a method of processing a data stream that includes video data. According to the method, one or more protocols used to create the data stream are identified. The various parsing and decoding operations required by the protocol are then identified and managed based on the available electrical power or available processing power. Another representative embodiment discloses a method of processing a data stream that includes video data. According to the method, one or more protocols used to create the data stream are identified. The various parsing and decoding operations required by the protocol are then identified and managed based on a visual quality of the video or a quality of experience.

RELATED APPLICATIONS

This application is related to U.S. patent application filed on the samedate as the present application, entitled POWER AND COMPUTATIONAL LOADMANAGEMENT TECHNIQUES IN VIDEO PROCESSING U.S. application Ser. No.12/336,362; and claims the benefit of U.S. Provisional Application Nos.61/090,176 filed Aug. 19, 2008, and 61/114,985 filed Nov. 14, 2008,which are all assigned to the assigner hereof and hereby expresslyincorporated by reference in each of their entirety for all purposes.

TECHNICAL FIELD

The present disclosure relates generally to the field of videoprocessing and, more specifically, to techniques for power andcomputational load management in video processing and decoding.

BACKGROUND

The amounts of digital information included in video data are massiveand tend to increase along with advances in performance of videocameras. Processing of the video data places large demands on power andcomputational resources of video-enabled devices and, in particular,wireless communication devices such as cellular phones, personal digitalassistants (PDAs), laptop computers, and the like.

Although video compression primarily reduces spatial and temporalredundancy, there are several pre-processing and post-processingoperations that are required after the source video has been captured(or extracted from storage as the case may be) and before thereconstructed video is rendered (consumed) at the display. VideoProcessing places large demands on memory (stored and data transfer) andcomputational load primarily due to the required arithmetic operationswhich are directly proportional to power requirements (battery, talktime, etc).

Given the amount of redundancy in video, a proportional reduction in thequantity of such operations should be expected. Since compression ratiosare many orders of magnitude (100:1 to 1000:1), a significant reductionin the amount of video data to be processed can be achieved in spite ofimplementation overheads. Spatio-temporal redundancy can be identifiedusing compression metadata and correspond to a reduction in redundantoperations, which saves power. Different levels of redundancy translateto different levels of consumed power and computational loading on aprocessor.

There is therefore a need for techniques for power and computationalload management in video processing and decoding.

SUMMARY

Techniques for managing power consumption and computational load on aprocessor in video processing and decoding are described herein. In oneconfiguration, an apparatus is provided that comprises a processorhaving a set of instructions operative to extract and compileinformation from a bitstream containing video data. The processor isoperative to identify one or more protocols used to create thebitstream, and then identify various parsing and decoding operationsrequired by the protocols. Once identified, the parsing and decodingoperations for the bitstream can then be managed based on the amount ofelectrical power available to the apparatus, or based on the availableprocessing power. According to one example, the identified parsingoperations and decoding operations of the bitstream may not be carriedout in their entirety, but instead may be selectively carried out basedon the available amount of electrical power or processing power.

According to another configuration, an apparatus is provided thatcomprises a processor having a set of instructions operative to extractand compile information from a bitstream containing video data. Theprocessor is operative to identify one or more protocols used to createthe bitstream, and then identify various parsing and decoding operationsrequired by the protocols. Once identified, the parsing and decodingoperations for the bitstream are managed based on a visual quality ofthe video or a quality of user experience. The apparatus also includes amemory coupled to the processor.

In another aspect, an integrated circuit (IC) comprising a processorhaving a set of instructions operative to extract and compileinformation from a bitstream having video is provided. The processor isoperative to identify one or more protocols used to create thebitstream, identify various parsing and decoding operations required bythe protocols, and then manage the parsing and decoding operations forthe bitstream based on the amount of electrical power available oravailable processing power. According to another configuration, theparsing and decoding operations are managed based on a visual quality ofthe video or a quality of user experience. The integrated circuit alsoincludes a memory coupled to the processor.

In another configuration, a computer program product including acomputer readable medium having instructions for causing a processor toextract and compile information from a bitstream containing video datais provided. The instructions further cause the processor to identifyone or more protocols used to create the bitstream as well as thevarious parsing and decoding operations required by the protocols, andthen manage the parsing and decoding operations based on the amount ofelectrical power available or available processing power. According toanother configuration, the parsing and decoding operations are managedbased on a visual quality of the video or a quality of user experience.

A further aspect of the configurations includes a processor thatorganizes the various parsing and decoding operations into groups, witheach group having a projected electrical power requirement or projectedprocessing power requirement. The processor then selects a group suchthat the groups projected electrical power or processing powerrequirement meets or does not exceed the available electrical power oravailable processing power. Alternatively, the various parsing anddecoding operations can be organized into groups based on a visualquality of the video or quality of user experience provided by theparsing and decoding operations associated with that group.

The summary is neither intended nor should it be construed as beingrepresentative of the full extent and scope of the present disclosure,which these and additional aspects will become more readily apparentfrom the detailed description, particularly when taken together with theappended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a general block diagram of a wireless device.

FIG. 2A shows a data stream

FIG. 2B shows a video layer data.

FIG. 2C shows a general MPEG format.

FIG. 2D shows a general MPEG bitstream with decodable units.

FIG. 3A shows a block diagram of a power management module and videoencoder and decoder engines.

FIG. 3B shows a block diagram of the decoder engine for use with thepower management module.

FIG. 4 shows a flowchart of a process for projecting power andcomputational loads for decoding prioritized power management (PM)sequences of decodable units.

FIG. 5 shows a transport layer (TL) parser and processing unit.

FIG. 6 shows a TL information extractor and compiler.

FIG. 7 shows a received time slice.

FIG. 8 shows a TL prioritized PM sequences of decodable units generator.

FIG. 9 shows a TL decoding MIPS and power projector.

FIG. 10 shows a process for decoding with power and computational loadmanagement.

FIG. 11 shows a multi-layer low power mode set generator during the TLmode.

FIG. 12 shows a video sequence/picture layer (VS/PL) parser andprocessing unit.

FIG. 13 shows a VS/PL extractor and compiler.

FIG. 14 shows VS/PL information in a received time slice.

FIG. 15 shows a VS/PL prioritized sequence to decode generator.

FIG. 16 shows a flowchart of a process to estimate MIPS by the VS/PLdecoding MIPS and power projector.

FIG. 17 shows a VS/PL decoding MIPS and power projector.

FIG. 18 shows a multi-layer low power mode set generator during theVS/PL mode.

FIG. 19 shows a slice/macroblock layer (S/MBL) parser and processingunit.

FIG. 20 shows an S/MBL extractor and compiler.

FIG. 21 shows an S/MBL prioritized sequence to decode generator.

FIG. 22 shows a multi-layer low power mode set generator during theS/MBL mode.

FIG. 23 shows a high level block diagram of the power managementoperations.

FIG. 24 shows an exemplary standard (normal) decoding process insequential order.

FIG. 25 shows a flowchart of a TL decoding process with power managementoperations.

FIG. 26 shows a flowchart of a VS/PL decoding process with powermanagement operations.

FIG. 27 shows a block diagram of a VS/PL information extractionprotocol.

FIG. 28 shows a block diagram of the VS/PL decoded units from thebitstream in accordance with the VS/PL information extraction protocol.

FIG. 29 shows a flowchart of an S/MBL decoding process with powermanagement operations.

FIG. 30 shows a block diagram of an S/MBL information extractionprotocol.

FIG. 31 shows a block diagram of S/MBL decoded units from the bitstreamin accordance with the S/MBL information extraction protocol.

FIG. 32 shows a block diagram of the final slice and macroblock decodingaccording to a selected power management mode.

FIG. 33 shows a block diagram of a hierarchical arrangement of themulti-layer power management modes.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures, except that suffixes may be added, when appropriate, todifferentiate such elements. The images in the drawings are simplifiedfor illustrative purposes and are not depicted to scale. It iscontemplated that features configurations may be beneficiallyincorporated in other configurations without further recitation.

The appended drawings illustrate exemplary configurations of thedisclosure and, as such, should not be considered as limiting the scopeof the disclosure that may admit to other equally effectiveconfigurations.

DETAILED DESCRIPTION

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any configuration or design described hereinas “exemplary” is not necessarily to be construed as preferred oradvantageous over other configurations or designs, and the terms “core”,“engine”, “machine”, “processor” and “processing unit” are usedinterchangeably.

The techniques described herein may be used for wireless communications,computing, personal electronics, handsets, etc. An exemplary use of thetechniques for wireless communication is described below.

FIG. 1 shows a block diagram of a configuration of a wireless device 10in a wireless communication system. The wireless device 10 may be ahandset. The wireless device 10 or handset may be a cellular or cameraphone, a terminal, a wirelessly-equipped personal digital assistant(PDA), a wireless communications device, a video game console, a laptopcomputer, a video-enabled device or some other wirelessly-equippeddevice. The wireless communication system may be a Code DivisionMultiple Access (CDMA) system, a Global System for Mobile Communications(GSM) system, or some other system.

The wireless device 10 is capable of providing bi-directionalcommunications via a receive path and a transmit path. On the receivepath, signals transmitted by base stations are received by an antenna 12and provided to a receiver (RCVR) 14. The receiver 14 conditions anddigitizes the received signal and provides samples to a digital section20 for further processing. On the transmit path, a transmitter (TMTR) 16receives data to be transmitted from the digital section 20, processesand conditions the data, and generates a modulated signal, which istransmitted via the antenna 12 to the base stations.

The digital section 20 includes various processing, interface and memoryunits such as, for example, a modem processor 22, a video processor 24,a controller/processor 26, a display processor 28, an ARM/DSP 32, agraphics processing unit (GPU) 34, an internal memory 36, and anexternal bus interface (EBI) 38. The modem processor 22 performsprocessing for data transmission and reception (e.g., modulation anddemodulation). The video processor 24 performs processing on videocontent (e.g., still images, moving videos, and moving texts) for videoapplications such as camcorder, video playback, and video conferencing.The video processor 24 performs video encoding and decoding or codecoperations. The video encoding and decoding operations may be performedby another processor or shared over various processors in the digitalsection 20. The controller/processor 26 may direct the operation ofvarious processing and interface units within digital section 20. Thedisplay processor 28 performs processing to facilitate the display ofvideos, graphics, and texts on a display unit 30. The ARM/DSP 32 mayperform various types of processing for the wireless device 10. Thegraphics processing unit 34 performs graphics processing.

The GPU 34 may be compliant, for example, with a document “OpenGLSpecification, Version 1.0,” Jul. 28, 2005, which is publicly available.This document is a standard for 2D vector graphics suitable for handheldand mobile devices, such as cellular phones and other referred to abovewireless communication apparatuses. Additionally, the GPU 34 may also becompliant with OpenGL2.0, OpenGL ES2.0, or D3D9.0 graphics standards.

The techniques described herein may be used for any of the processors inthe digital section 20, e.g., the video processor 24. The internalmemory 36 stores data and/or instructions for various units within thedigital section 20. The EBI 38 facilitates the transfer of data betweenthe digital section 20 (e.g., internal memory 36) and a main memory 40along a bus or data line DL.

The digital section 20 may be implemented with one or more DSPs,micro-processors, RISCs, etc. The digital section 20 may also befabricated on one or more application specific integrated circuits(ASICs) or some other type of integrated circuits (ICs).

The techniques described herein may be implemented in various hardwareunits. For example, the techniques may be implemented in ASICs, DSPs,RISCs, ARMs, digital signal processing devices (DSPDs), programmablelogic devices (PLDs), field programmable gate arrays (FPGAs),processors, controllers, micro-controllers, microprocessors, and otherelectronic units.

Raw video data may be compressed in order to reduce the amount ofinformation that must be transmitted to or processed by wireless device10 or other video-enabled device. Compression may be performed using,for example, video coding techniques compliant with one or more ofindustry-adapted video compression and communication standards,including those standards by ISO/IEC's Moving Picture Expert GroupMPEG-2 and MPEG-4, ITU-T's H.264/AVC, or others (AVC stands for AdvancedVideo Coding). Video coding techniques compliant with non-standardcompression methods such as VP6 used in Adobe Flash player may also beused to generate the compressed video data. In the configurations, theraw and compressed video data may be transmitted to, from, or within thewireless device 10 or other video-enabled device using wireless or wiredinterfaces or a combination thereof. Alternatively, the compressed datamay be stored in media such as DVDs.

The compressed video data is encapsulated in a payload format fortransmission using transport protocols using, for example, InternetProtocol (IP) as defined by IETF in Real Time Transport Protocolspecifications.

FIG. 2A shows a block diagram of a data stream and the correspondingprotocols that must be transmitted or processed by wireless device 10 orother video-enabled device. A data stream, 2141, comprised of transportlayer data 2142, for example, encapsulation as specified by thetransport protocol specification, 2145, and video layer data, 2143. Thetransport layer data follows format or syntax or semantics of datarepresentation as specified in the corresponding transport protocol andvideo layer data follows format or syntax or semantics forrepresentation of video data as specified in video coding protocol,2144, such as the compression standards.

A Transport Protocol 2145 encapsulates video layer data for transmissionor storage, e.g. file format like MP4 or transport format such as RTP orUDP or IP. A Video Coding protocol 2144 can be a video coding standardsuch as MPEG-2 or MPEG-4 or H.264/AVC or any other video codec such asReal Video or Windows Media etc. The syntax and semantics of thetransport layer data is governed or specified by the transport protocoland syntax and semantics of the video layer data is governed orspecified by the video coding protocol.

FIG. 2B shows the format of the video layer data, 2143. The video layerdata comprises a sequence or group of pictures (GOP) or a picture layerdata, 2243, a slice or macroblock (MB) layer data, 2254 and a blocklayer data, 2247.

At the receiver, when the data stream is received, in traditionalsystems, the video processor parsers and decodes the data stream in theorder specified by the corresponding transport protocol specificationand the video coding protocol or standard specification. The transportparser unwraps the encapsulation in an order corresponding to thetransport protocol specification herein referred to as normal parsingoperation. The video decoder parsers and decodes the video layer data inan order specified by the video coding protocol or standardspecification herein referred to as normal decoding operation.

In the described system and methods below, the video processorselectively parses and/or decodes or processes parts of the data streamand the order of the parsing and/or decoding and processing operationsis based on available power, available computational processing power orvisual quality.

FIG. 2C shows a general MPEG packet format 50. An MPEG packet format isan example of a data stream, 2141. The MPEG packet format 50 includes aplurality of MPEG layers 52, 54, 56, 58, 60, 62 and 64. The MPEG layersinclude a transport layer 52, a sequence layer 54, a group of pictures(GOP) layer 56, a picture layer 58, a slice layer 60, a macroblock (MB)layer 62 and a block layer 64. In FIG. 2A, the layers are shown stackedto represent a hierarchical order of layers that require decoding andprocessing. For the purposes of description herein, the sequence andpicture layers 54 and 58 are grouped together and called a videosequence/picture layer (VS/PL) 70 for the purposes of power loadmanagement described herein. In some standards, only a sequence layermay be present or a picture layer or a combination of layers.Additionally, the slice and macroblock (MB) layers 60 and 62 are groupedtogether to form a slice/MB layer (S/MBL) 72 for the purposes of powerload management described herein. In some standards, one or more of thelayers may be omitted or combined.

In MPEG compression, video frames may be coded and formatted into agroup of pictures (GOP) which may include one or more of an intra-coded(I) frame, a predictive-coded (P) frame, and a bidirectionallypredictive-coded (B) frame. Some B-frames may be reference frames.Non-reference B-frames may be designated as b-frames. As can beappreciated, describing all the frames and arrangement of frames in thestandards is prohibitive.

FIG. 2D shows a general MPEG bitstream with decodable units. Thebitstream includes, at the sequence layer 54, a sequence header 54Afollowed by sequence data 54B. The sequence layer 54 is a decodableunit. The sequence data 54B includes the picture layer 58 which includesa plurality of pictures denoted as picture 1, picture 2, picture 3, . .. , picture (N−1) and picture N. Each picture is a decodable unit. Eachpicture includes a picture header 58A and picture data 58B. The picturedata 58B includes the slice layer 60. The slice layer 60 includes aplurality of slices denoted as slice 1, slice 2, slice 3, slice (M−1)and slice M. Each slice is a decodable unit. The slice includes a sliceheader 60A followed by slice data 60B. The slice data 60B of a sliceincludes the macroblock layer 62. The macroblock layer 62 includes aplurality of macroblocks denoted as MB 1, MB 2, MB 3, . . . , MB (P−1)and MB P. Each macroblock is a decodable unit. Each macroblock includesa MB header 62A and MB data 62B. Some decodable units are dependent onanother decodable unit. Thus, prioritization will take intoconsideration dependent decodable units. Moreover, one or more of thedecodable units in each layer are divisible.

FIG. 3A shows a block diagram of a power management module 100 and videoencoder and decoder engines 102 and 104. The power management module 100has a multi-level low power mode set generator 114. The multi-level modeset generator 114 has a plurality of low power modes arranged inaccordance with the hierarchical (tiered) layers of the MPEG format. Theplurality of low power modes are based on prioritized power management(PM) sequences of decodable units that may be selectively decoded forimproved granularity and/or visual quality at each layer. Granularitymay refer to the extent of parsing or decoding operations that can beexecuted to maximize the resulting visual quality for a given powerconsumption target. PM sequences are sequences of decoding or parsingoperations that facilitate power management. PM sequences attempt tomaximize visual quality for a given power through look-ahead processingof selective decode and/or parsing operations. The multi-level low powermode set generator 114 has a plurality of layer modes. In thisconfiguration, the plurality of layer modes includes a TL mode, a VS/PLmode and a SL/MB mode. As can be appreciated, the techniques describedherein are not limited to the MPEG format but may be used with othervideo compression and/or transport protocol formats.

In one embodiment, information from a data stream including video datais extracted and compiled and based on this information, the sequencesof decoding and parsing operations for the data stream that facilitatespower management (PM sequences) is prioritized.

In another embodiment, the prioritization is based on look-aheadprocessing of at least one of decoding and parsing operations. In yetanother embodiment, projections of at least one of power andcomputational loading for each of the prioritized PM sequences iscalculated. In another embodiment, the prioritizing of power managementsequences is based on at least one of visual quality and granularity.

The embodiments further comprise generating a hierarchical list of lowpower modes or quality modes to selectively decode the prioritized powermanagement sequences, based on the prioritization. Different low powermodes or quality modes correspond to different degrees of visualquality. The selection of a low power mode may be in response toavailable power or computational loading. In addition, the selectivedecoding of one or more of the prioritized power management sequencesmay be in response to the selected low power mode. In anotherembodiment, the selective decoding may be based on calculatingprojections of at least one of power and computational loading for theprioritized power management sequences.

In the exemplary configuration, degrees of redundancy indicated byprediction modes, for example, yields a graduated set of layers which inturn can be mapped to a graduated set of low/reduced power operationalmodes. One format using H.264 prediction modes is based on the fact thatthe level of redundancy in video in decreasing order corresponding tointer and intra prediction modes includes: Skip, Direct, Inter, andIntra prediction modes. The order of modes also corresponds to differingdegrees of visual quality when compromised (when inaccuracies areintroduced in decoding and reconstruction of MBs corresponding to thesemodes). These concepts can be extended to other video coding standardsand formats.

To exploit the redundancy in video toward power optimized videoprocessing, several aspects involving the decoder engine 104 only,encoder engine 102 only or coordinated across the encoder and decoderengines may be employed for power load management. In the case of adecoder engine only (DO) solution, the DO solution may be applied duringdecoding or rendering at the device 10 and are encoder agnostic. Thesolutions may be are divided into conformant and non-conformantcategories. A conformant category solution would output a video streamwhich maintains standards conformance. Here, strict conformancerequirements are to be met. In a non-conformant solution, an advantageof this solution is flexibility and larger reduction (compared toconformant) in complexity for minimal impact to visual quality.

In the case of an encoder engine 102 only (EO) solution, all complexityreduction methods are incorporated during encoding and are decoderagnostic. In the EO solution all encoding functions are biased from theperspective of processing power. Optionally, a cost function forprocessing power is included in rate-distortion (RD) optimizationsreferred to as RD-power optimizations.

In the case of a joint encoder-decoder engine (JED) solution, powerreduction methods are incorporated or adopted during the encoding andthe decoder engine performs appropriate reciprocal actions to provideincreased reduction (in power/load/cost). In the JED solution, theencoder engine is aware of the capabilities of the decoder engine toapply DO solution methods described above and incorporates indicatorsfor appropriate actions in the bitstream (user field or supplementalenhancement information (SEI) messages) or side channel for use at thedecoder engine. A previously agreed upon protocol based on a set ofpower reduction would may be adopted by both encoder and decoder enginesfor increased reduction in power/load/cost.

DO solutions apply to open ended applications where the decoder engineis unaware of the encoding process. Examples would include Mobile TV,Video-On-Demand (VOD), PMP, etc. The EO solutions would find applicationin video servers where power friendly bitstreams are required to drivelow power devices. The EO solution is also useful in scenarios wheremultiple coded versions of a source are generated and a network serveradaptively selects/switches between them based on network/channelconditions. JED solutions provide the most gain in terms of powerreduction for a given quality compared to DO or EO solution methods. TheJED solution apply to closed or conversational applications where acommunications/control path (real-time or apriori) is possible.

The description below is directed to DO solutions and provides amulti-layer framework configuration to regulate implementation andoperational complexity in video decoding. Load management in videodecoding and rendering operations are possible where an extended videoplayback is required by various applications such as Mobile TV, portablemultimedia player (PMP), (movie/DVD players), etc. The techniquesdescribed herein embodied in the multi-layer framework configuration maybe extended to any video or multimedia application.

Load or power management refers to regulation of run-time complexityincluding but not limited to delays, power consumption and millioninstruction per second or processor cycles (MIPS) availability.Regulation includes optimizing the user experience, in particular, videoquality given the available processing, power and time resources.Regulation may also be done to optimize a quality of experience (QoE) ofthe user, which may encompass other performance factors besides videoquality, such as for example, audio quality, response time, quality ofgraphics, etc. The multi-layer framework configuration allows suchregulation at various levels of granularity for both precautionary andreactionary responses to instantaneous demands on the video decoderimplementation by the application(s). Alternate execution orcontrol/data flow paths are recommended based on available informationand power (battery) levels or desired visual quality. In view of theforegoing, the description provided herein is primarily directed to DOoperations as performed by the decoder engine 104. The video decoding bythe decoder engine 104 may be followed by rendering, performed by arendering stage 28A (FIG. 23) in the display processor 28.Decoding/rendering does not have to be a serial process. For example,multiple slices could be decoded in parallel, rows of an image may berendered in parallel or in a waveform fashion which may not beconsidered serial. Nonetheless, although decoding followed by renderingin serial order is the norm, in one configuration these operations areparallelized. Rendering typically includes post-processing (color-spaceconversion, scaling, etc.) followed by compositing the image to bedisplay and the display process (transferring to a display buffer,reading from this buffer and writing to display). For the sake ofexample, decoding is followed by rendering in a serial process andoccurs in chronological order (timing is based on decode time stamps fordecoding and presentation time stamps for rendering/displaying). Howeverthe input to this process (decoding and rendering) is a video bitstream(except maybe in the case of the viewfinder) which is not necessarilyprioritized by order of importance in terms of visual quality (i.e.Instantaneous Decoder Refresh (IDR), intraframe (I) and predicted (P)frames are interspersed). Also, the transport layer protocol thatdelivers the video bitstream to the decoder engine 104 does so inpackets which are presented to the decoder engine 104 in order ofpacket/sequence numbers. Processing the bitstream in the received ordermay result in frame drops and does not allow for throttling the qualityof the output video for low power operations (either user-initiated toconserve battery or modulated by the system based on available orallocated power). Lack of processor cycles, MIPS and/or accumulateddelays and latencies may result in key frames, typically larger in size,being dropped causing video to stall for long durations.

The encoder engine 102 acquires or generates and compresses video datain compliance with MPEG standards, H.264 or other standards. The videodata is processed to extract a selected portion of video information sothat encoding meets image quality, power, and/or computational loadrequirements of the device 10 and/or transmission capabilities of anoutput video interface, bandwidth or other characteristics of the device10 or video-enabled device (for example, wireless or wired interface).Additionally, encoding may be such that decoding (by a recipient) meetsquality, power and/or computational requirements and capabilities of therecipient's decoder engine or receiver 14.

FIG. 3B shows a block diagram of the decoder engine 104 for use with thepower management module 100. The decoder engine 104 includes a standard(normal) sequence decoding processing unit 105 to decode the bitstreamwhen power management or a low power mode is not necessary. The decoderengine 104 also includes a transport layer (TL) parser and processingunit 106, a video sequence/picture layer (VS/PL) parser and processingunit 108, a slice/MB layer (S/MBL) parser and processing unit 110, ablock layer parser and processing unit 112. In the exemplaryconfiguration, power and computation load management at the block layer64 is not described.

As will be seen from the description below, the TL parser and processingunit 106 parses and processes the transport layer 52. The VS/PL parserand processing unit 108 parses and processes at least the sequence layer54 and the picture layer 58. The combination of the sequence layer 54and the picture layer 58 is herein after referred to as a videosequence/picture layer (VS/PL) 70. However, the VS/PL parser andprocessing unit 108 may also parse and process the GOP layer 56 or someother parser and processing unit may be employed for the GOP layer 56.Thus, the line from the reference numeral 70 to the GOP layer 56 isshown in phantom. The S/MBL parser and processing unit 110 parses andprocesses the slice layer 60 and the macroblock (MB) layer 62. The blocklayer parser and processing unit 112 parses and processes the blocklayer 64 in order to decode the video or programming in the MPEG format.

One or more of the parser and processing units 106, 108, 110, and 112may be employed to operate in parallel, separately or in a combinedrelationship to carryout the power and computational load managementfunctions described herein. Furthermore, one or more of the power andcomputational load management functions of the parser and processingunits 106, 108, 110, and 112 may be omitted. Nonetheless, in theexemplary configuration, the parser and processing units 106, 108 and110 are selectively actuated as necessary to provide a tiered power andcomputational load management function which controls the visualquality, trading visual quality for power loading and granularity in anyone of the tiers so as to also maintain or enhance the user's experiencewhile using power efficiently.

FIG. 4 shows a flowchart of a process 120 for projecting power andcomputational loads for decoding prioritized power management (PM)sequences of decodable units. In order to prioritize the bitstream andthe consequent power management (PM) sequences of decodable units forselective decoding, a three-phase (3-phase) process 120 is provided foreach hierarchical (tiered) layer to provide hierarchically arranged lowpower operational modes. The process 120 relies on non-causality in thevideo bitstream and its efficiency depends on the amount of look-ahead(decoder engine's input buffer depth).

The process 120 begins at block 122 where parsing and extracting layerinformation takes place. Block 122 is followed by block 124 where thosePM sequences (not to be confused with the sequence layer) of decodableunits requiring decoding are prioritized. For illustrative purposes, theprioritized PM sequences of decodable units are shown in the form of alist, as will be described in more detail later. The term “prioritizedPM sequences of decodable units,” will hereinafter sometimes be referredto as “prioritized PM sequences.” However, each sequence includes one ormore divisible decodable units. A decodable unit comprises one or moreor groups of a picture, a slice, and macroblocks, as will be seen fromthe following description.

Block 124 is followed by block 126 where the power and computation loadfor the prioritized PM sequences are projected. In the exemplaryconfigurations, the computational load is projected as a function of thenumber of million instructions per second (MIPS). A corresponding MIPSrequires a projected or predetermined power.

At block 126, there is a correlation of the prioritized PM sequences tocorresponding MIPS and, subsequently, the power required to decode oneor more of the PM sequences. Blocks 122 and 124 are described below withrespect also the H.264 standard. Block 126 may use the results frompower analysis corresponding to typical scenarios (e.g. test bitstreams)and, optionally, feedback driven training or run-time updates for use inthe projection. Once a bitstream is known, the power and computationloads (processing power) may be projected to inform the user whetherthere is not enough power in the device 10 to decode the bitstream tocompletion. Thus, if the power (battery or electrical power) would bedepleted prior to the bitstream being completely decoded (such as duringplayback), the user has an option to select a power mode that wouldallow the bitstream to be completed.

As previously mentioned, the 3-phase process 120 can be repeated for thedifferent layers in the compression data format. After each block 126(corresponding to different layers), a hierarchical set of low powermodes are generated for the decoder engine 104 to utilize for power andcomputational load management of the decoding operations. This canhappen on the fly or it may be predetermined for a set of appropriatelychosen bitstreams and the decoder calibrated/programmed in advance priorto real-time operations.

FIG. 5 shows a transport layer (TL) parser and processing unit 106. TheTL parser and processing unit 106 includes a TL information extractorand compiler 150 (FIG. 6), a TL prioritized PM sequences generator 152(FIG. 8) and a TL decoding MIPS and power projector 154 (FIG. 9). Thetransport layer (TL) parser and processing unit 106 will carryout thethree-phase process 120 for use in power and computational loadmanagement of the decoding operations for the transport layer 52.

FIG. 6 shows a TL information extractor and compiler 150. The TLinformation extractor and compiler 150 depends on the transport protocolover which the video bitstream is received. An example, of a portion ofa received time slice 190 is shown in FIG. 7. In the exemplaryconfiguration, the various information in the bitstream can be extractedand compiled by the TL information extractor and compiler 150. The TLinformation extractor and compiler 150 will parse the received timeslice 190 shown in FIG. 7. The TL information extractor and compiler 150includes a random access point (RAP) extractor 160, a state informationextractor 166, a bitstream characteristics extractor 176 and a transportlayer information compiler 186. The RAP extractor 160 may extractinformation 162 having location, size, presentation time stamp (PTS),etc. of packets/slices flagged as acquisition. The RAP extractor 160 mayalso extract the sequence of RAPs 164 in the transport header (e.g.entry-point header in the real-time transport protocol (RTP) payloadformat). In the exemplary configuration, the extracted stateinformation, by the state information extractor 166, includesinformation regarding a channel change 170 and a user viewingpreferences 172 (such as in broadcast or mobile TV applications). Theextracted state information 166 may also include a change in application174 (e.g. resolution/preview mode or picture-in-picture mode), etc.

The bitstream characteristics extractor 176 extracts a bitrate 178, aframe rate 180, a resolution 182, an application (stored vs. streaming)184, etc. In the case of the bitrate 178, values are readily availablein some cases (e.g. MPEG file format). In other cases, the bitrate iscomputed, such as by the transport layer information complier 186, basedon the size of bitstream over a second indicated by time stamps aftertransport headers and padding are removed. The TL layer informationextractor and compiler 150 includes a TL information compiler 186 tocompute the information that is not directly extractable from thetransport layer of the received time slice. Example calculations for apacket size and bitrate are described in relation to FIG. 9.

FIG. 7 shows the received time slice 190 in this example with RAP₁ 191,RAP₂ 196, . . . RAP_(N) 198 in the received data. (It could optionallybe a section of the bitstream extracted from a stored file). Each RAP,such as RAP₁ 191, has a header 192 followed by a payload 193 having datapertaining the coded frame that is the random access point, such as anI-frame. The header includes a plurality of fields, one of which is aPTS₁ interval 194. The absolute RAP locations (packets) and PTS valuesfrom the PTS₁ interval 194 for each RAP are computed (e.g. in RTP,derived from random access (RA) count and reference time and PTSoffset). RAP₂ 196 has a header followed by a payload having datapertaining to the coded frame that is the random access point, such asan I-frame. The header includes a plurality of fields, one of which is aPTS₂ interval.

An interval denoted as RAP-GOP is defined as a group of pictures thatbegins with a RAP frame until the next RAP frame. At the transportlayer, the RAP is a decodable unit. Furthermore, the RAP-GOP may be adecodable unit for the transport layer. Based on the application, moredata is retrieved or requested if needed. For example, during playbackof stored video, it may be possible to seek through file format headersfor a few seconds (2-5 seconds) worth of data to assess the bitrate andframe rate. Then, based on the available power, decide on decoding allof the data or decode toward a reduced frame rate.

The received time slice 190 may be a superframe for MediaFLO™ or a timeslice for digital video broadcast (DVB) such as DVB-H (where H standsfor handheld).

FIG. 8 shows TL prioritized PM sequences generator 152. The informationextracted above is processed to create a list of TL prioritized PMsequences of decodable units 200. The TL prioritized PM sequencesgenerator 152 derives absolute parameter values. Assume at the transportlayer 52, a plurality of packets RAP₁, RAP₂, . . . RAP_(N) 191, 196 and198 with corresponding GOPs have been received. Thus, the TL prioritizedPM sequences of decodable units to be decoded by the decoder engine 104begins with block 202. Here the decodable units are RAP₁ at block 202,the rest of RAP-GOP₁ at block 204, RAP₂ at block 206, the rest ofRAP-GOP₂ at block 208. The prioritizing of TL prioritized PM sequencescontinues until the decodable unit RAP_(N) at block 210 and the rest ofthe RAP-GOP_(N) at block 212. The above description of TL prioritized PMsequences of decodable units is just one example of an arrangement ofsequences.

FIG. 9 shows a TL decoding MIPS and power projector 154. At thetransport level 52, a first level of power/computation load reductionsare possible. This level may provide coarse power/computational loadreductions. For example, for the lowest power mode setting or when abattery level of device 10 has been depleted to <10%, only the RAPpackets (denoted by blocks 202, 206 and 210) would be decoded and, whilerendering by the rendering stage 28A, optionally, the graphicsprocessing unit 34 may be triggered to create transition effects betweenthe I-frames. The transition effects provide a low cost “video” insteadof a slide show effect. Based on the low power mode, other videocompensations may be used to compensate for skipped decodable units. Forexample, image morphing may be employed. Another example of compensationmay employ optical flow.

The TL decoding MIPS and power projector 154 generates datarepresentative of a projection (column 4) for the MIPS to decode one,more or all of the PM sequences of decodable units in the list of TLprioritized PM sequences 200. For illustrative and descriptive purposesonly, a MIPS projection table 230 is shown. The table has a plurality ofcolumns. In column C1, the transport layer information or the TLprioritized PM sequences of decodable units are itemized. In column 2,the packet size to decode the some or all of the decodable units isidentified. In column C3, the bitrate calculation is identified. Incolumn C4, the projected MIPS to decode the decodable units is provided.As can be appreciated, the bitrate in column C3 and the packet size incolumn C2 may have been derived during the prioritization phase.

In this example, row R1 identifies a first decodable unit in the list ofTL prioritized PM sequences of decodable units 200. In this instance,the first decodable unit is RAP₁. The packet size of RAP₁ can becalculated based on the extracted and compiled information from the TLextractor and compiler 150. In the exemplary configuration, the decodepacket size for RAP₁ corresponds to the size of the transport packet forRAP₁—the size of (transport header 192 plus the payload 193). The decodepacket size for RAP₂ corresponds to the size of the transport packet forRAP₂—the size of (transport header plus the payload). Likewise, thedecode packet size for RAP_(N) corresponds to the size of the transportpacket for RAP_(N)—the size of (transport header plus the payload). Inrow RN+1 (the last row) corresponds to the entire received time slice,such as slice 190. Thus, a projection of the MIPS is calculated for eachdecodable unit and all decodable units at row RN+1 for the entiretransport layer 52 of the received time slice 190.

In column 3, the bit rate is calculated or extracted. In this case, thebitrate is calculated based on the sizes of RAP, GOP₁, PTS₂, PTS₁according to the size of the interval (RAP-GOP₁) divided by the size ofthe interval (PTS₂−PTS₁) or (PTS₂ minus PTS₁). The bitrate for RAP₂, . .. RAP_(N) is calculated in a similar manner as RAP₁. In row RN+1, thebitrate is the size of the received time slice/interval (PTS₂−PTS₁).

In column 4, in row R1, the projected MIPS to decode RAP₁ has twovalues. The first value is a function of the I-frame size for RAP₁. Thesecond value is a function of that portion of the bitstream of size(RAP-GOP₁) for the given codec. The information for the projection ofthe MIP is available from the transport headers (RAP and thecorresponding PTS). Thus, the decodable units divisible and are notfully decoded when projecting the MIPS. Instead, only the header or aportion thereof needs to be decoded to extract the necessaryinformation, as will be described in more detail below. In row RN+1, theprojected MIPS to decode the entire time slice is projected according tobitstream size (for the time slice) for the given codec. It should benoted that the MIPS projection to decode for the specified quantity is afunction of power profiling and analysis.

For each of the MIPS projection in column C4, a corresponding powerrequirement can be determined. The corresponding power can be calculatedas needed or may be pre-stored in a lookup table. This will generallycomplete the third phase of the three-phase process 120.

FIG. 10 illustrates a process 240 for decoding with power andcomputational load management. Given the MIPS requirement to decode oneor more of the decodable units, and the available MIPS at a giveninstant, (or power requirement vs. available power/amps), the decisionto decode all or part of the received time slice 190 can be made. Theprocess 240 is illustrated with the third phase of process 120 shown inphantom. The third phase of the process 120 provides the necessaryprojections for computational loads and/or power necessary to decode thetransport layer 52. Thus, at block 242, the MIPS are projected. At block244, the power corresponding to the projected MIPS is determined. Whilethe exemplary configuration provides for a MIPS and power relationship,other values which affect the power and computational loads may beemployed.

Block 244 ends the third phase. Block 244 is followed by blocks 246where the available MIPS (computational load) for a given instant isdetermined. Block 244 is also followed by block 248 where the availablepower is determined for a given instant. Blocks 246 and 248 are shown inparallel. Nonetheless, in various configurations, the blocks of theprocess 240 and other processes described herein are performed in thedepicted order or at least two of these steps or portions thereof may beperformed contemporaneously, in parallel, or in a different order.

Block 246 is followed by block 250 where a determination is made whetherthe projected MIPS is greater than the available MIPS. If thedetermination is “No,” meaning the available computation load at theinstant is sufficient, then all of the transport layer 52 can be decodedat block 254. However, if the determination at block 250 is “Yes,”meaning the available computation load is insufficient, then part of thetransport layer 52 can be decoded in accordance with any of the modesidentified in the list of low power mode settings 260 (FIG. 11) at block256.

Block 248 is followed by block 252 where a determination is made whetherthe projected power is compared to the available power. If thedetermination at block 252 is “No,” meaning that the available power issufficient, then all of the transport layer 52 may be decoded. However,if the determination at block 252 is “Yes,” meaning the available poweris insufficient, then part of the transport layer 52 can be decoded atblock 256 in accordance with any of the modes identified in list of lowpower mode settings 260 (FIG. 11). All of the transport layer 52 wouldbe decoded if both conditions from blocks 250 and 252 are No. Thetransport layer 52 would be decoded in part for all other cases. Theblocks 248, 252 are shown in phantom to denote that they are alsooptional.

FIG. 11 shows a multi-layer low power mode set generator 114 during theTL mode. The multi-layer low power mode set generator 114 generates alist of selectable low power mode settings 260. In the exemplaryconfiguration of FIG. 11, there are a plurality of transport layer lowpower modes denoted as mode 1 in row R1, mode 1A in row 2 and mode 2 inrow 3. The transport layer mode 1 corresponds, for example, to aslideshow using all the RAPs (hereinafter referred to as “SS-RAP”). Thetransport layer mode 1A corresponds to the SS-RAP with transitioneffects by the rendering stage 28A. Thus, mode 1A differs from mode 1 inthat mode 1A provides an enhanced visual quality over mode 1. Thetransport layer mode 2 corresponds to selectively decoding RAP-GOPsbased on the available power. The list in column C2 would provide thenecessary instruction to cause the decoder engine 104 to selectivelydecode one or more of the decodable units at the transport layer 52.

The power management module 100 during the TL mode makes a determinationbased on the projected MIPS and/or power which one low power mode 1, 1Aor 2 can be afforded to the user for the decoding of the bitstream. Mode2 may be selected if there is available power which may be furtherconserved based on managing the power of other layers of decodableunits, as will be described in relation to the video sequence/picturelayer.

If TL mode 1A is selected, normal decoding of the SS-RAPs (I-frames)with transition effects takes place. However, if TL mode 1 is selected,the power management module 100 may proceed to VS/PL mode 3 for furtherupgrades in visual quality.

Sequence/Picture Layer

FIG. 12 shows a video sequence/picture layer (VS/PL) parser andprocessing unit 108. The VS/PL parser and processing unit 108 includes aVS/PL information extractor and compiler 280 (FIG. 13), a VS/PLprioritized PM sequences generator 282 (FIG. 15) and a VS/PL decodingMIPS and power projector 284 (FIG. 17). The VS/PL parser and processingunit 108 will carryout the three-phase process 120 for use inpower/computational load management of the decoding operations for theVS/PL 70.

FIG. 13 shows a VS/PL information extractor and compiler 282. The VS/PLinformation extractor and compiler 282 depends on the VS/PL format ofthe video bitstream. An example, of a received time slice 330 accordingto the VS/PL 70 is shown in FIG. 14. Based on the video codec (encoderengine and decoder engine), information is extracted at the sequencelayer 54. In the case of MPEG-2 and MPEG-4, the video sequence layerparameters are extracted. This requires an interface into the videodecoder engine 104. The extraction will be described later in relationto FIG. 27 and 28.

If some parameters listed at the transport layer 52 could not beretrieved (e.g. I-frame locations or packet ID), such information may beextracted at the sequence layer 54. The VS/PL information extractor andcompiler 280 extracts the I-frame location 284 and the packet ID 286.The VS/PL information extractor and compiler 282 also extracts a profile290, a level 292, and parameter constraints (constrained_set_flags) 294from the sequence parameter set (SPS) such as for the H.264 standard orthe sequence layer 54. The picture parameter set (PPS) may also be used.

The VS/PL information extractor and compiler 282 may also extract orcompile picture information 296. The picture information may include anumber of reference frames 298, resolution 300, frame rate 302 (if notalready retrieved), display parameters (VUI), etc. to assess thecomputational load required to decode/process the data. Additionalinformation includes information regarding reference location 304,reference picture size 306, PTS and reference picture information 308.Non-reference picture locations 310, non-reference picture size 312,non-reference picture information 314 and the PTS also may be extractedor compiled. An information that is compiled is complied by theinformation compiler 316. In order to extract the VS/PL information, thesequence header and all picture headers are decoded only. The payload ofthe picture is left un-decoded, as will be described in more detail inFIGS. 27 and 28.

FIG. 15 shows a VS/PL prioritized PM sequences generator 282. At theVS/PL prioritized PM sequences generator 282 absolute parameter valuesare derived from the extracted information. The list of VS/PLprioritized PM sequences of decodable units 360 is populated with moredetails for improved granularity. The prioritization is similar to thatdiscussed in relation to FIG. 8. At this level or layer, however, theplurality of packets RAP₁, RAP₂, . . . RAP_(N) (blocks 362, 382, 388)identified in the transport layer 52 are further qualified orprioritized based on the type of I-frame such as IDR and I-frame in thecase of H.264. Alternatively, all I-frames are identified using thepicture header information and are then prioritized.

In the exemplary configuration, the block or interval RAP-GOP₁ 364 isfurther sub-divided into other VS/PL decodable units. These VS/PLdecodable unit are further prioritized such that IDRs (or I-frames atthe beginning of a closed GOP in MPEG-2) are followed by a non-IDRI-frames (open GOP). Hence, prioritization may be set so that IDR-frames366 are followed by I-frames 368. I-frames 366 are followed by P-frames370 which are followed by reference B-frames 372. The reference B-frames372 are then followed by non-reference B-frames denoted as b-frames 374.FIG. 14 shows a received time slice 330 indicating frame types (P, B andb).

Thus, the VS/PL prioritized PM sequences to be decoded by the decoderengine 104 begins with RAP₁ at block 362 which is followed the RAP-GOP₁at block 364. The RAP-GOP₁ is further prioritized according to blocks366, 368, 370, 372 and 374. The interval corresponding to the RAP-GOP₁can be further prioritized based on the b-frame. In the exemplaryconfiguration, the VS/PL prioritized PM sequence is further prioritizedusing size information for b-frames at blocks 376-380. For example,b-frames having a size information larger than the FRUC threshold,denoted as, FRUC_THR, (block 376) may have a higher priority than thoseb-frames with a size which is less than the FRUC threshold.Additionally, b-frames smaller than a Drop threshold, denoted asDROP_THR, may be flagged and dropped entirely with no FRUC. Thus, atblock 378, the prioritization criteria may be set asDROP_THR<b<FRUC_THR. At block 380, the prioritization criteria may beset as b<DROP_TH. These thresholds can be mapped to percentage reductionin processing cycles/power required.

Block 382 sets the prioritization for decoding RAP₂. Block 384 isfollowed by block 382 where the prioritization for the rest of theRAP-GOP₂ is prioritized similar to blocks 366, 368, 370, 372, 374, 376,378 and 380 above. The prioritization of the VS/PL prioritized PMsequences continue at block 386 until block 388 for prioritizing thedecoding of RAP_(N). Block 388 is followed by block 390 where the restof the RAP-GOP_(N) is prioritized for decoding.

Depending on a status of the computational load, the sequence ofdecoding operations may be reduced or modified through elimination of anappropriate number of low priority sequences or selectable decodableunits.

FIG. 16 shows a flowchart of a process 400 to project MIPS by the VS/PLby the VS/PL decoding MIPS and power projector 284. The process 400begins with block 402 where MIPS to decode an IDR-frame sizes aredetermined. Block 402 is followed by block 404 where the MIPS to decodeall I-frames sizes are determined. Block 404 is followed by block 406where the MIPS to decode all the P-frames sizes are determined. Block406 is followed by block 408 where the MIPS to decode all B-frames sizesare determined. Block 408 is followed by block 410 where the MIPS todecode all b-frames sizes is determined with various conditions. Forexample, if some of the b-frames (such as a b₁ frame and b₂ frame) aredropped, the projected MIPS to decode is set to 0.

FIG. 17 shows a VS/PL decoding MIPS and power projector 284. At theframe level; frame type (such as IDR, I, P, B, b . . . ), size (306 or312) and the frame rate 302 are key factors (other qualifiers may beincluded), that can be used to assess the amount or proportion ofprocessor cycles required to decode them. Power profiling and analysisusing specific test bitstreams can be used to derive a relationshipbetween the amount of processor cycles and frame size based on frametype (IDR, I, P, B, b . . . ). These relationships may be arranged in alookup table for later use in the MIPS and power projections. Otherconditions may be fixed during this analysis and extrapolated later. Forexample, the mapping may be derived for 1-reference picture scenario andrelative complexity vs. 5-reference pictures may be extrapolated basedon independent analysis. In the case of the H.264 standard, frame levelinformation is not available until slice headers are parsed.

In FIG. 17, the VS/PL decoding MIPS and power projector 284 generates alist of projected MIPS to decode 440. The list is generated forillustrative and descriptive purposes. At row R1, the VS/PL decodingMIPS and power projector 284 projectors for the IDR-frames based on thesize(IDR) of each IDR. At row R2, the VS/PL decoding MIPS and powerprojector 284 generates the projected MIPS for all I-frames based on asequence of sizes I-frame sizes (size(I₁), size(I₂), . . . ). At row R3,the VS/PL decoding MIPS and power projector 284 generates the projectedMIPS for all P-frames based on P-frame sizes (size(P₁), size(P₂), . . .). At row R4, the VS/PL decoding MIPS and power projector 284 generatesthe projected MIPS for all B-frames based on B-frame sizes (size(B₁),size(B₂), . . . ) At row R5, the VS/PL decoding MIPS and power projector284 generates the projected MIPS for all B-frames (non-referenceB-frames) based on B-frame sizes (size(b₁), size(b₂), . . . ). Whenprojecting the MIPS for all b-frames, a determination is made whether b₁and b₂ are dropped. If so, then the projected MIPS is set to zero (0).There is also a projection in relation to FRUC in place of b1, b2, . . ., etc.

In relation to FIGS. 10 and 17, for each of the MIPS projections in thelist of projected MIPS to decode 450, a corresponding power requirementis applied. Given the MIPS requirement, and the available MIPS at agiven instant, (or power requirement vs. available power/amps), thedecision to decode all or selected frames (part), which are decodableunits, can be made in a similar manner as described above in relation toFIG. 10.

At the end of sequence/picture level processing, medium granularitypower reduction modes are possible (reductions from 0-60% in steps of 5%are possible—assuming that an I-frame typically constitutes 30% of bitsin a GOP and the number of bits is proportional to the MIPSrequirement). Depending on feedback on current status of processor loadand power levels, the sequence of operations is shortened throughelimination of appropriate number of low priority entities. Modespossible at the sequence/picture layer are listed in FIG. 18 in order ofincreasing power requirements.

FIG. 18 shows a multi-layer low power mode set generator 114 during theVS/PL mode. The multi-layer low power mode set generator 114 generates alist of low power modes 450. The list is generated for illustrativepurposes. The list includes a VS/PL Layer Mode 3 corresponding toinstructions to decode a Slideshow using RAPs and all I-frames. Thus, ifmode 1A is selected, the power management module 100 would evaluate ifadditional MIPS are available such that all of the I-frames may also bedecoded for improved visual quality or granularity. VS/PL Layer Mode 3is followed by a VS/PL Layer Mode 4A corresponding to instructions todecode based on a reduced frame rate using all I-frames and P-framesonly. VS/PL Layer Mode 4A is followed by VS/PL Layer Mode 4Bcorresponding to instructions to decode based on a reduced frame rateusing all I-frames and P-frames only with selective FRUC in place ofB-(and b) frames. At mode 4B, the I and P-frames are decoded usingnormal decoding. However, the B-frames are not decoded. Instead,selective FRUC is substituted in place of each B or b-frame for all B orb-frames. VS/PL Layer Mode 4B is followed by VS/PL Layer Mode 4Ccorresponding to instructions to selectively decode RAP-GOPs based onavailable power such as the I-frames and P-frames as above. However, asan alternate operation, the selective FRUC is used in place of each B orb-frame for a selective number of B or b-frames. VS/PL Layer Mode 4C isfollowed by VS/PL Layer Mode 4D corresponding to instruction to decodebased on a reduced frame rate (higher than mode 4C) using all I andP-frames. All B-frames may be also included. Alternately, and theselective FRUC is used in place of each B-frame (optionally forselective number of B-frames) and no operation is used for the b-frames.Alternately, the b-frames may be skip or by-passed. VS/PL Layer Mode 4Dis followed by VS/PL Layer Mode 5 corresponding to instructions todecode all received frames (I, P, B and b).

If the VS/PL Layer mode 3 or 5 was selected, a further alternateoperation would be to replace with skip macroblocks (MBs). Furthermore,from mode 2, further enhanced visual quality or granularity may beachieved by the refinements afforded by the modes 4A-4D and 5.

Slice/MB Layer

FIG. 19 shows a slice/macroblock layer (S/MBL) parser and processingunit 110. The S/MBL parser and processing unit 110 includes a S/MBLinformation extractor and compiler 460 (FIG. 20), a S/MBL prioritized PMsequences generator 462 (FIG. 21) and a S/MBL decoding MIPS and powerestimator 464. The S/MBL parser and processing unit 110 will carryoutthe three-phase process 120 for use in power/load management of thedecoding operations for the S/MBL 72.

FIG. 20 shows a S/MBL information extractor and compiler 460. The S/MBLinformation extractor and compiler 460 depends on the protocol orstandard for which the video bitstream has been compressed. Here, theS/MBL information extractor and compiler 460 extracts slice information470 and MB information 472. Slice information 470 and MB headers areparsed for the pictures corresponding to those identified in theprioritized sequence from FIG. 15. A select portion of the frames fromthe prioritized sequence (FIG. 15) in the previous layer VS/PL 70 mightbe flagged to be decoded. Note that, decoding may continue for allpictures if finer granularity of power management is required. Thus,only the slice headers and MB headers are decoded.

If headers are detected to be in error, coefficient/MB data for the MBor entire slice may be discarded. Optionally, zero MV concealment may beapplied and refined later with more sophisticated error correction (EC).The MB information 472 includes MB type 474, motion vectors (MVs) 476,mode 478, size 480, other information 482 and MB maps per frame 484.

An exemplary MB maps per frame is described in patent application Ser.No. 12/145,900 filed concurrently herewith and is incorporated herein byreference as if set forth in full below.

FIG. 21 shows a S/MBL prioritized PM sequences generator 462. The listof S/MBL prioritized PM sequences 490 uses the slice information and MBmaps to estimate the complexity of each frame in the prioritized list inFIG. 15. In one configuration, only P-frame slices at block 492 andB-frame slices at block 502 are further prioritized. At the previouslylayer, all I-frames are to be decoded for any selected mode in theVS/PL. The P-frame slices are further prioritized based on the ROI MBsper slice at block 494 and Non-ROI MBs with mode smoothing at block 496.The mode smoothing is further prioritized according to forced uniformmotion at block 498 and forced P-skips at block 500. The B-frame slicesare further prioritized based on the ROI MBs per slice at block 504 andNon-ROI MBs with mode smoothing at block 506. The mode smoothing isfurther prioritized according to forced uniform motion at block 507 andforced B-skips at block 508.

Mode smoothing may be applied to group MBs with similar characteristics.For every 3×3 or 5×5 window of MBs, the windows of MBs are assessed foruniformity of modes. Outliers (MB with mode that is different fromremaining MBs) in the window are identified. If outliers are marginallydifferent, they are forced to a mode of the window. Otherwise, the modefor the outlier is maintained. For example, if in a 3×3 MB window, oneMB is inter mode while the others are skip and if the residual(indicated by CBP or MB size) of the inter MB is less than aSkip_threshold, the MB is forced to skip mode. After mode smoothing, theproportion of skip vs. direct/inter mode MBs is computed and included asa factor of complexity. Additionally, connected regions of skip MBs maybe combined as tiles through MB dilation and MB erosion (as in thepatent application Ser. No. 12/145,900. Tiles can then be qualified asskip/static, non-static, uniform motion, region-of-interest (ROI, basedon relative MB/tile size) etc. In the case of uniform motion tile, MVsof the MBs may be quantized and the tile may be forced to one MV (notethat this may be done provided the residual/CBP of these MBs are zero oralmost zero). Another option is where only non-static or ROI tiles aredecoded and rest are forced to be skipped. In this case, some of thenon-ROI MBs may be of modes other than skip but will be forced to skipsuch as in blocks 500 and 508.

FIG. 22 shows a multi-layer low power mode set generator 114 during theS/MBL mode. The multi-layer low power mode set generator 114 generates ahierarchical list of low power modes 650. The ability to manipulatewhich of the MBs in a frame and which of the received frames areprocessed provides a significant level of granularity in managing thedecoding and rendering process. In addition, the above described MBlevel power optimization may be performed during decoding (on-the-fly).Again, detailed profiling and power analysis is required to map theproportion of reduction in power to the corresponding low power mode.

The examples of modes are described as S/MBL mode 6A, 6B, 6C, 7A, 7B, 7Cand 8. In mode 6A, the I-frames are decoded per normal decoding of theI-frames. However, additional alternate operations may take place toimprove visual quality or granularity as power permits. For example, inmode 6A, the P-frames with non-ROI MBs may be forced to P_Skips and B-and b-frames may be forced to selective FRUC. In mode 6B, I-frames aredecoded as per normal decoding of I-frames. Alternate operations in mode6B may include forcing P-frames with mode smoothing to P_Skips and B-and b-frames to selective FRUC. In mode 6C, the I-frames are decodedaccording to the normal decoding process. However, as an alternateoperation, P-frames with mode smoothing may be forced uniform motion andB- and b-frames may be forced to selective FRUC. In mode 7A, the I andP-frames are decoded according to the normal decoding process. However,as an alternate operation, B-frames with non-ROI MBs are forced toSkips. In mode 7B, the I and P-frames are decoded according to thenormal decoding process. However, as an alternate operation, B-frameswith mode smoothing are forced to Skips. In mode 7C, the I and P-framesare decoded according to the normal decoding process. However, as analternate operation, B-frames with mode smoothing are force uniformmotion. In mode 8, all received frames (I, P, B and b) are decoded.

FIG. 23 shows a high level block diagram of the power managementoperations. The block diagram includes the decoder engine 104 incommunication with a rendering stage 28A of the display processor 28.Thus, the power management (PM) module 100 processes the bitstreams atthe TL mode, VS/PL mode and the S/MBL modes. The PM module 100 controlsthe decoder engine 104 to decode the decodable units according to thelow power mode selected. The processing required during rendering isalso derived from the prioritized sequence of operations from theframework in any of the low power mode of operations described above.Furthermore, the output of the decoder engine 114 may be sent to otherdevices, memory, or apparatus. The output from the decoder may beforwarded to another video enabled apparatus for eventual storage orconsumption (display). The graphics processing unit 34 is also incommunication with the display processor 28

FIG. 24 illustrates an exemplary standard (normal) decoding process 700in sequential order. The process 700 is also described in relation toFIG. 2D. Beginning at the video sequence and picture layer, the standard(normal) decoding process 700 will decode a sequence header 54A at block702 followed by decoding a picture header 58A of picture 1 at block 704.After decoding the picture header of picture 1, the picture data 58B isdecoded which includes the slice and macroblock information. Thus, whenthe picture 1 data decoded, all of the slice units are decoded denotedby slice 1-M. Since each slice is decoded similarly, only one slice willbe described in more detail.

When slice 1 is decoded, the slice header 60A of slice 1 of picture 1 isdecoded at block 706. Then, the MB header 62A of macroblock (MB) 1 ofslice 1 of picture 1 is decoded at block 708. After, the MB header 62Aof the MB1 is decoded, the related MB data for MB1 of slice 1 of picture1 is decoded at block 710. Then the next macroblock is obtained. Thus,the MB header 62A of macroblock (MB) 2 of slice 1 of picture 1 isdecoded at block 712. After, the MB header of the MB2 is decoded, therelated MB data 62B for MB2 of slice 1 of picture 1 is decoded at block714. The decoding of the macroblock header followed by the related MBdata 62B continues for all remaining MBs in the slice. In this example,there are N MBs. Thus, the decoding of slice 1 of picture 1 would endwith decoding the MB header for MB N of slice 1 of picture 1 at block716 followed by decoding the related MB data 62B of MB N of slice 1 ofpicture 1 at block 718.

Thus, the process 700 would continue decoding the picture 1 informationby decoding each of the remaining slices in a similar manner asdescribed above for slide 1. In this example, there are M slices. Thus,at block 720, the slice M is decoded in the manner as described above inrelation to blocks 706-718.

Next, the process 700 would decode the next picture frame such aspicture 2. To decode picture 2, the process 700 would decode the pictureheader 58A of picture 2 at block 722 to derive the locations for slices1-M, Thus, at block 724, the slice 1 is decoded in the manner asdescribed above in relate to blocks 706-718. All remaining slices ofpicture 2 are decoded similarly. Thus, at block 726, the slice M isdecoded in the manner as described above in relation to blocks 706-718to complete the decoding of picture 2.

The process 700 repeats the decoding of all the picture framessequentially in a similar manner until the last picture Z. In thisexample, there are pictures 1-Z. Hence to decode the last picture,picture Z, the process 700 would decode the picture header 58A ofpicture Z at block 728 followed by slice 1 decoding at block 730. Eachslice is decoded in picture Z until slice M at block 732.

FIG. 25 illustrates a flowchart of a TL decoding process 800 with powermanagement operations. The process 800 begins with block 802 where TLinformation extraction and TL prioritization of the PM sequences ofdecodable units takes place, as described in relation to FIGS. 6 an 8.Block 802 is followed by block 804 where the MIPS and/or power loadingare projected for the TL prioritized PM sequences. Block 804 is followedby block 806 where the MIPS for the TL low power mode set is projected.Block 806 is followed by block 808 where a determination is made whetherthere is enough power to decode the bitstream. If the determination is“YES,” then the normal decoding process 700 may take place at block 810in accordance with the procedure described in relation to FIG. 24.However, if the determination is “NO,” then as an option, the user maybe notified that there is insufficient power such as to playback a videoat block 812. The user would be given low power mode optionscorresponding to modes 1, 1A and 2 from which to select. Alternately,the low power mode may be selected automatically. Block 812 is followedby block 814 where a TL low power mode is selected whether by a user orautomatically. The flowchart of FIG. 25 proceeds to FIG. 26.

FIG. 26 illustrates a flowchart of a VS/PL decoding process 900 withpower management operations. The process 900 begins with performing atblock 902 the VS/PL information extraction and VS/PL prioritizing the PMsequences, such as described in FIGS. 13 and 15. At block 904, the MIPSfor all frames types (decodable units) are projected as described inrelated to FIGS. 16 and 17. At block 906, the MIPS and/or power loadingfor each VS/PL low mode set, as shown in FIG. 18, is projected based onthe VS/PL prioritized PM sequences. Based on the projected MIPS, PMsequences are grouped together based on visual quality and granularity.Some of the sequences (such as all sequences) may not be decoded becauseof insufficient power. Thus, at block 908, a ranked sub-set of low powermodes from the VS/PL low power mode set that is below the maximumavailable power may be generated. The ranking is a function of improvedvisual quality and/or granularity. At block 910, optionally, the usermay be notified of the limited power and provided a selection of lowpower mode options. At block 912, the best ranked low power mode of thesub-set may be selected or the low power mode selected by the user. Atblock 914, based on the selected VS/PL low power mode, decoding beginsby interjecting the decoding operations back into the normal decodingprocess 700 of FIG. 24 as appropriate.

In one configuration, after each frame is decoded based on one selectedlow power mode, the MIPS may be re-projected. Thereafter, the next frameor other un-decoded frames in the bitstream may be decoded using adifferent selected mode. Thus, the low power mode may be dynamicallychanged or generated on the fly during the decoding of the bitstream.

FIG. 27 illustrates a block diagram of a VS/PL information extractionprotocol 902A which diverges from the normal decoding process 700 ofFIG. 24. In FIG. 27, the VS/PL information extraction protocol 902A willdecode the sequence header 54A at block 950. Thus, the location of thepictures 1-N is derived as denoted by the arrow above each block denotedfor pictures 1-N. At block 952, the picture header 58A of picture 1 isdecoded. At block 954 the picture header 58A of picture 2 is decoded.All picture headers are decoded. At block 956, the picture header forpicture Z (the last picture) is decoded. Thus, the decoding of thepicture headers 58A allows the PM sequences of decodable units to bederived for a particular bitstream and the MIPS projected for the PMsequences of decodable units.

FIG. 28 illustrates a block diagram of the VS/PL decoded units from thebitstream in accordance with the VS/PL information extraction protocol902A. The sequence header 54A is shown hatched to denote that thesequence header 54A has been decoded. Furthermore, the picture headers58A for each of the pictures 1-N are shown hatched to denote that thepicture headers 58A have been decoded. The picture data 58B remainsunhatched to denote that it remains undecoded at this point. Thesequence data 54B also remains un-decoded. The decoding of the pictureheaders 58A allows the necessary slice locations to be obtained for theslice and macroblock layer without decoding the picture data.

FIG. 29 illustrates a flowchart of a S/MBL decoding process 1000 withpower management operations. The process 1000 begins at block 1002 withperforming the S/MBL information extraction and S/MBL prioritizing ofthe PM sequences of decodable units, such as described in FIGS. 20 and21. In one configuration, only information for the P and B-frames areextracted and prioritized. At block 1004, the MIPS for each of the S/MBLlow power modes are re-projected. At block 1006, a ranked sub-set of lowpower modes from the S/MBL low power mode set that is below the maximumavailable power is generated. The ranking is a function of improvedvisual quality and/or granularity. At block 1008, optionally, the usermay be notified of the limited power and provided a selection of lowpower mode options. At block 1010, the best ranked low power mode of thesub-set may be selected or the low power mode selected by the user. Atblock 1012, based on the selected S/MBL low power mode, P and B-frameslice and MB data decoding begins by interjecting the decodingoperations back into the normal decoding process 700 of FIG. 24 asappropriate. After block 1012, the MIPS may be re-projected after one ormore frames have been decoded so that the low power mode may be upgradedor downgraded according to the remaining available power.

FIG. 30 illustrates a block diagram of a S/MBL information extractionprotocol 1002A which diverges from the normal decoding process 700 ofFIG. 24. FIG. 30 will be described in conjunction with FIG. 31. FIG. 31illustrates a block diagram of a S/MBL decoded units from the bitstreamin accordance with the S/MBL information extraction protocol 1002A. TheS/MBL information extraction protocol 1002A will decode the picture data58B for the first picture 1. To decode the picture data 58B, only theslice header 60A and MB header 62B are decoded until a low power modecan be selected. The arrows above the blocks for pictures 1-N indicate alocation of the picture. The black shading of the arrows denotes theselection of the picture based on a low power mode. The non-shadedarrows denotes a picture that has not been selected. At block 1050, theslice header 60A for picture 1 is decoded at block 1050. At block 1052,the MB header 62A of MB 1 of slice 1 of picture 1 is decoded. At block1054, the MB header 62A of MB 2 of slice 1 of picture 1 is decoded. Allmacroblock headers for slice 1 of picture 1 are decoded where at block1056, the MB header for MB N of slice 1 of picture 1 is decoded. Themacroblock data 62B is not decoded. The hatching of picture data 58B,slice header 60A and MB header 62A denotes decoding thereof.

The slice header 60A of each slice is decoded followed by the decodingof the MB header of each MB of a slice. The, at block 1058, slice M (thelast slice) of picture 1 is decoded in a similar manner as block1050-1056. All remaining pictures are decoded in a similar manner. Atblock 1060, the picture Z (the last picture) is decoded as describedabove in relation to blocks 1050-1058. Thus, the decoding of the sliceand macroblock headers allows the PM sequences of decodable units to bederived for a particular bitstream and the MIPS projected for the PMsequences of decodable units.

FIG. 32 illustrates a block diagram of the final slice and macroblockdecoding according to a selected power management mode. The slice data60B and the MB data 62B are decoded according to the PM sequences to bedecoded for the selected low power mode (such as modes 6A-6C and 7A-7C).The slice data 60B and the MB data 62B are shown hatched to indicatedecoding thereof.

FIG. 33 illustrates a block diagram of a hierarchical arrangement of themulti-layer power management modes. The TL PM processing 1200 begins thefirst tier of power management at the transport layer 52. As the resultof the TL PM processing 1200, a plurality of low power modes areestablished based on the projected MIPS. In one configuration, modes 1,1A and 2 are proposed. The power management operations continue to asecond tier at VS/PL PM processing 1202. The second tier of powermanagement is conducted at the sequence and picture layer 70. The VS/PLPM processing 1202 produces a plurality of low power modes as a functionof projected MIPS and visual quality and/or granularity. In oneconfigurations, modes 3, 4A-4D are generated. Mode 5 is a power mode butmay not be a low power mode if all frames are decoded. Nonetheless, thepower management operations continue to a third tier at S/MBL PMprocessing 1204. The third tier of power management is conducted at theslice and macroblock layer 72. The S/MBL PM processing 1204 produces aplurality of low power modes as a function of projected MIPS and visualquality and/or granularity. In one configurations, modes 6A-6C and 7A-7Care generated. Mode 8 allows all the frames to be decoded if powerpermits. Furthermore, mode 8 may be used after a part of the bitstreamhas been decoded and the re-projection of the MIPS indicates that allremaining frames may be decoded.

In one or more exemplary configurations, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

The previous description of the disclosed configurations is provided toenable any person skilled in the art to make or use the disclosure.Various modifications to these configurations will be readily apparentto those skilled in the art, and the generic principles defined hereinmay be applied to other configurations without departing from the spiritor scope of the disclosure. Thus, the disclosure is not intended to belimited to the configurations shown herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

The invention claimed is:
 1. A method of processing a data stream,comprising the steps of: receiving a data stream that includes videodata; identifying a transport protocol and a video coding protocol usedto create the data stream; identifying various parsing and decodingoperations required by the transport protocol and the video codingprotocol; prioritizing a plurality of sequences of decodable units fromthe data stream for at least one of selective parsing or selectivedecoding based on the identified parsing and decoding operations;evaluating an amount of available electrical power and an amount ofavailable processing power; and managing the various parsing operationsand decoding operations for the data stream based on the amount ofavailable electrical power and the amount of available processing power,wherein the managing of the various parsing operations and decodingoperations comprises selectively carrying out the parsing and decodingoperations for the data stream, and wherein selective parsing ordecoding comprises parsing or decoding at least one higher prioritysequence at a higher granularity or visual quality than a lower prioritysequence to maximize the resulting visual quality corresponding to apower consumption target.
 2. The method of claim 1, further comprisingthe step of: associating the various parsing operations and decodingoperations into groups wherein each group has at least one of aprojected electrical power requirement and a projected processing powerrequirement.
 3. The method of claim 2, further comprising the step of:prioritizing the groups into a hierarchical list of low power modesbased on at least one of the projected electrical power requirement andprojected processing power requirement.
 4. The method of claim 2,further comprising the step of: selecting a group such that at least oneof the selected group's projected electrical power requirement andprojected processing power requirement meets or does not exceed theavailable electrical power and available processing power, respectively.5. The method of claim 3, further comprising the steps of: presentingthe hierarchical list of low power modes to a user; receiving an inputindicating the low power mode selected by the user; and selecting agroup of parsing operations and decoding operations in response to theinput.
 6. A method of processing a data stream, comprising the steps of:receiving a data stream that includes video data; identifying atransport protocol and a video coding protocol used to create the datastream; identifying various parsing and decoding operations required bythe transport protocol and the video coding protocol; prioritizing aplurality of sequences of decodable units from the data stream for atleast one of selective parsing or selective decoding based on theidentified parsing and decoding operations; and managing the variousparsing operations and decoding operations for the data stream based onat least one of a visual quality of the video and a quality ofexperience (QoE), wherein the managing of the various parsing operationsand decoding operations comprises selectively carrying out the parsingand decoding operations for the data stream, and wherein selectiveparsing or decoding comprises parsing or decoding at least one higherpriority sequence at a higher granularity or visual quality than a lowerpriority sequence to maximize the resulting visual quality correspondingto a power consumption target.
 7. The method of claim 6, furthercomprising the step of: associating the various parsing operations anddecoding operations into groups wherein each group corresponds to adegree of visual quality of the video or a degree of quality ofexperience.
 8. The method of claim 7, further comprising the step of:prioritizing the groups into a hierarchical list of quality modes basedon at least one of the degree of visual quality of the video and degreeof quality of experience.
 9. The method of claim 7, further comprisingthe step of: selecting a group such that at least one of the selectedgroup's visual quality of the video and quality of experience satisfiesa desired degree of visual quality of the video and desired degree ofquality of experience, respectively.
 10. The method of claim 8, furthercomprising the steps of: presenting the hierarchical list of qualitymodes to a user; receiving an input indicating the quality mode selectedby the user; and selecting a group of parsing operations and decodingoperations in response to the input.
 11. A device for processing a datastream, comprising: a processor configured to execute a set ofinstructions operable to: receive a data stream that includes videodata; identify a transport protocol and a video coding protocol used tocreate the data stream; identify various parsing and decoding operationsrequired by the transport protocol and the video coding protocol;prioritize a plurality of sequences of decodable units from the datastream for at least one of selective parsing or selective decoding basedon the identified parsing and decoding operations; evaluate an amount ofavailable electrical power and an amount of available processing power;and manage the various parsing operations and decoding operations forthe data stream based on the amount of available electrical power andthe amount of available processing power, wherein the managing of thevarious parsing operations and decoding operations comprises selectivelycarrying out the parsing and decoding operations for the data stream,and wherein selective parsing or decoding comprises parsing or decodingat least one higher priority sequence at a higher granularity or visualquality than a lower priority sequence to maximize the resulting visualquality corresponding to a power consumption target.
 12. The device ofclaim 11, wherein the processor is further configured to executeinstructions to: associate the various parsing operations and decodingoperations into groups wherein each group has at least one of aprojected electrical power requirement and a projected processing powerrequirement.
 13. The device of claim 12, wherein the processor isfurther configured to execute instructions to: prioritize the groupsinto a hierarchical list of low power modes based on at least one of theprojected electrical power requirement and projected processing powerrequirement.
 14. The device of claim 12, wherein the processor isfurther configured to execute instructions to: select a group such thatat least one of the selected group's projected electrical powerrequirement and projected processing power requirement meets or does notexceed the available electrical power and available processing power,respectively.
 15. The device of claim 13, wherein the processor isfurther configured to execute instructions to: present the hierarchicallist of low power modes to a user; receive an input indicating the lowpower mode selected by the user; and select a group of parsingoperations and decoding operations in response to the input.
 16. Adevice for processing a data stream, comprising: a processor configuredto execute a set of instructions operable to: receive a data stream thatincludes video data; identify a transport protocol and a video codingprotocol used to create the data stream; identify various parsing anddecoding operations required by the transport protocol and the videocoding protocol; prioritize a plurality of sequences of decodable unitsfrom the data stream for at least one of selective parsing or selectivedecoding based on the identified parsing and decoding operations; andmanage the various parsing operations and decoding operations for thedata stream based on at least one of a visual quality of the video and aquality of experience (QoE), wherein the managing of the various parsingoperations and decoding operations comprises selectively carrying outthe parsing and decoding operations for the data stream, and whereinselective parsing or decoding comprises parsing or decoding at least onehigher priority sequence at a higher granularity or visual quality thana lower priority sequence to maximize the resulting visual qualitycorresponding to a power consumption target.
 17. The device of claim 16,wherein the processor is further configured to execute instructions to:associate the various parsing operations and decoding operations intogroups wherein each group corresponds to a degree of visual quality ofthe video or a degree of quality of experience.
 18. The device of claim17, wherein the processor is further configured to execute instructionsto: prioritize the groups into a hierarchical list of quality modesbased on at least one of the degree of visual quality of the video anddegree of quality of experience.
 19. The device of claim 17, wherein theprocessor is further configured to execute instructions to: select agroup such that at least one of the selected group's visual quality ofthe video and quality of experience satisfies a desired degree of visualquality of the video and desired degree of quality of experience,respectively.
 20. The device of claim 18, wherein the processor isfurther configured to execute instructions to: present the hierarchicallist of quality modes to a user; receive an input indicating the qualitymode selected by the user; and select a group of parsing operations anddecoding operations in response to the input.
 21. An apparatus forprocessing a data stream, comprising: means for receiving a data streamthat includes video data; means for identifying a transport protocol anda video coding protocol used to create the data stream; means foridentifying various parsing and decoding operations required by thetransport protocol and the video coding protocol; means for prioritizinga plurality of sequences of decodable units from the data stream for atleast one of selective parsing or selective decoding based on theidentified parsing and decoding operations; means for evaluating anamount of available electrical power and an amount of availableprocessing power; and means for managing the various parsing operationsand decoding operations for the data stream based on the amount ofavailable electrical power and the amount of available processing power,wherein the means for managing the various parsing operations anddecoding operations selectively carries out the parsing and decodingoperations for the data stream, and wherein selective parsing ordecoding comprises parsing or decoding at least one higher prioritysequence at a higher granularity or visual quality than a lower prioritysequence to maximize the resulting visual quality corresponding to apower consumption target.
 22. The apparatus of claim 21, furthercomprising: means for associating the various parsing operations anddecoding operations into groups wherein each group has at least one of aprojected electrical power requirement and a projected processing powerrequirement.
 23. The apparatus of claim 22, further comprising: meansfor prioritizing the groups into a hierarchical list of low power modesbased on at least one of the projected electrical power requirement andprojected processing power requirement.
 24. The apparatus of claim 22,further comprising: means for selecting a group such that at least oneof the selected group's projected electrical power requirement andprojected processing power requirement meets or does not exceed theavailable electrical power and available processing power, respectively.25. The apparatus of claim 23, further comprising: means for presentingthe hierarchical list of low power modes to a user; means for receivingan input indicating the low power mode selected by the user; and meansfor selecting a group of parsing operations and decoding operations inresponse to the input.
 26. An apparatus for processing a data stream,comprising: means for receiving a data stream that includes video data;means for identifying a transport protocol and a video coding protocolused to create the data stream; means for identifying various parsingand decoding operations required by the transport protocol and the videocoding protocol; means for prioritizing a plurality of sequences ofdecodable units from the data stream for at least one of selectiveparsing or selective decoding based on the identified parsing anddecoding operations; and means for managing the various parsingoperations and decoding operations for the data stream based on at leastone of a visual quality of the video and a quality of experience (QoE),wherein the means for managing the various parsing operations anddecoding operations selectively carries out the parsing and decodingoperations for the data stream, and wherein selective parsing ordecoding comprises parsing or decoding at least one higher prioritysequence at a higher granularity or visual quality than a lower prioritysequence to maximize the resulting visual quality corresponding to apower consumption target.
 27. The apparatus of claim 26, furthercomprising: means for associating the various parsing operations anddecoding operations into groups wherein each group corresponds to adegree of visual quality of the video or a degree of quality ofexperience.
 28. The apparatus of claim 27, further comprising: means forprioritizing the groups into a hierarchical list of quality modes basedon at least one of the degree of visual quality of the video and degreeof quality of experience.
 29. The apparatus of claim 27, furthercomprising: means for selecting a group such that at least one of theselected group's visual quality of the video and quality of experiencesatisfies a desired degree of visual quality of the video and desireddegree of quality of user experience, respectively.
 30. The apparatus ofclaim 28, further comprising: means for presenting the hierarchical listof quality modes to a user; means for receiving an input indicating thequality mode selected by the user; and means for selecting a group ofparsing operations and decoding operations in response to the input. 31.A computer program product including a non-transitory computer readablemedium storing instructions which, when executed by a processor, causethe processor to: receive a data stream that includes video data;identify a transport protocol and a video coding protocol used to createthe data stream; identify various parsing and decoding operationsrequired by the transport protocol and the video coding protocol;prioritize a plurality of sequences of decodable units from the datastream for at least one of selective parsing or selective decoding basedon the identified parsing and decoding operations; evaluate an amount ofavailable electrical power and an amount of available processing power;and manage the various parsing operations and decoding operations forthe data stream based on the amount of available electrical power andthe amount of available processing power, wherein the managing of thevarious parsing operations and decoding operations comprises selectivelycarrying out the parsing and decoding operations for the data stream,and wherein selective parsing or decoding comprises parsing or decodingat least one higher priority sequence at a higher granularity or visualquality than a lower priority sequence to maximize the resulting visualquality corresponding to a power consumption target.
 32. The computerprogram product of claim 31, further comprising instructions which, whenexecuted by a processor, cause the processor to: associate the variousparsing operations and decoding operations into groups wherein eachgroup has at least one of a projected electrical power requirement and aprojected processing power requirement.
 33. The computer program productof claim 32, further comprising instructions which, when executed by aprocessor, cause the processor to: prioritize the groups into ahierarchical list of low power modes based on at least one of theprojected electrical power requirement and projected processing powerrequirement.
 34. The computer program product of claim 32, furthercomprising instructions which, when executed by a processor, cause theprocessor to: select a group such that at least one of the selectedgroup's projected electrical power requirement and projected processingpower requirement meets or does not exceed the available electricalpower and available processing power, respectively.
 35. The computerprogram product of claim 33, further comprising instructions which, whenexecuted by a processor, cause the processor to: present thehierarchical list of low power modes to a user; receive an inputindicating the low power mode selected by the user; and select a groupof parsing operations and decoding operations in response to the input.36. A computer program product including a non-transitory computerreadable medium storing instructions which, when executed by aprocessor, cause the processor to: receive a data stream that includesvideo data; identify a transport protocol and a video coding protocolused to create the data stream; identify various parsing and decodingoperations required by the transport protocol and the video codingprotocol; prioritize a plurality of sequences of decodable units fromthe data stream for at least one of selective parsing or selectivedecoding based on the identified parsing and decoding operations; andmanage the various parsing operations and decoding operations for thedata stream based on at least one of a visual quality of the video and aquality of experience (QoE), wherein the managing of the various parsingoperations and decoding operations comprises selectively carrying outthe parsing and decoding operations for the data stream, and whereinselective parsing or decoding comprises parsing or decoding at least onehigher priority sequence at a higher granularity or visual quality thana lower priority sequence to maximize the resulting visual qualitycorresponding to a power consumption target.
 37. The computer programproduct of claim 36, further comprising instructions which, whenexecuted by a processor, cause the processor to: associate the variousparsing operations and decoding operations into groups wherein eachgroup corresponds to a degree of visual quality of the video or a degreeof quality of experience.
 38. The computer program product of claim 37,further comprising instructions which, when executed by a processor,cause the processor to: prioritize the groups into a hierarchical listof quality modes based on at least one of the degree of visual qualityof the video and degree of quality of experience.
 39. The computerprogram product of claim 37, further comprising instructions which, whenexecuted by a processor, cause the processor to: select a group suchthat at least one of the selected group's visual quality of the videoand quality of experience satisfies a desired degree of visual qualityof the video and desired degree of quality of experience, respectively.40. The computer program product of claim 37, further comprisinginstructions which, when executed by a processor, cause the processorto: present the hierarchical list of quality modes to a user; receive aninput indicating the quality mode selected by the user; and select agroup of parsing operations and decoding operations in response to theinput.